cesses of remote induction and uncertain inference. The distance and the extent of the farthest and mightiest firmament have begun to be distinctly defined to us, and have, therefore, come wholly within the grasp of conception; while the molecule and the realm of its intense and swiftly consummating activities remain still indefinitely removed from us, and unconceived and unconceivable. It is here that the truest indefinite lies for us.

Far more incomprehensible, however, to our present knowledge, than the mere distance and extent of these firmaments of suns, are, with regard to many of them, their internal arrangements as associated systems, and the nature of the motions and orbits of the constituent orbs. Have these orbs motions at all?

It is, of course, impossible for us yet to have sensible manifestation of these; and hopeless to expect it for centuries or more than centuries to come. Yet firmamental arrangement and motion have now become inextricably associated in our minds; and with the satisfactory establishment of the long-suspected orbitual movement of our sun, there has grown up an increasing difficulty in our conceiving any heavenly orb, or even any aggregation of orbs, at rest. Hitherto, seek where we may, we have not found rest throughout all the physical universe. Upon earth we have found the rivers run unto the sea, and the sea is not full,' for its waters stream up to the clouds, and the clouds flow down upon the hills, and the water-springs of the hills find the rivers again; and, restful and sluggish though they seem, 'surely the mountain falling is coming to nought, and the rock 'being removed out of its place.' And in the heaven above us, we might almost say still more decisively, rest has nowhere presented itself to our observation, but everywhere motion, the type and the symbol of change: the visible and tangible prophecy, if not of consummation and entire dissolution, at least of change so entire and universal, that in comparison of what now they are, the heavens shall indeed pass away like a scroll. Nay more; motion now presents itself to us as the great instrumental means for the maintaining of order among these crowding orbs; for the restoring of interrupted balance, and the preservation of perfect harmony. And if it be beginning to reveal itself as also the great mediative means whereby all that now is shall be extensively, it may be wholly, changed, we may rest well assured that this also has been foreappointed, and that this progression shall issue, if not in the evolution of a yet more glorious physical universe, yet in the clearer illustration of His infinitude and eternity, whose creative will is the ever-present sustenance, guidance, and controlment of all.

We are constrained, then, to regard motion as one element

of the activities of all these orbs of heaven. We find the moon gliding on her path around the earth; the earth, with its fair subordinate, circling around the sun; the sun, with his girdling worlds and their girdling moons, sweeping along his firmamental path. There is much in the aspect of some of these far-off firmaments to make us wonder what the strange movements of their constituent orbs may be, and what the devious, irregular, undefinable paths they traverse: nothing to make us except them from that all-prevalence of action and motion which all advance of research hitherto has but brought before us as the more all-prevalent. Cases are not wanting, indeed, where we have little difficulty in conceiving, and within certain limits of possible error defining, the probable nature of those stellar paths. There are, for example, clusters, the forms of which are so nearly globular, that we are comparatively safe in assuming the orbits of the stars composing them to be not far removed from those of the earth or her sister planets,-curves more or less elliptical, or approaching the ellipse, having for their centre of impulsion the general centre of the forces of the firmament. But such cases are comparatively rare; and in one or two such, which have been subjected to the examination of Lord Rosse's instruments, the former apparent simplicity of clustering has expanded into recondite and complex irregularity. And especially such systems as those which we have endeavoured to describe, as having grown out of what were considered irresolvable nebulæ, baffle for the present all attempts definitely to realise the paths of the constituent orbs. When we turn, for instance, to the annular system in Lyra,* could we remove the interior and exterior filaments, it were not very difficult to assign, for the stars of the ring itself, a probable path which, though peculiar, were not irregular, a double motion of translation, which bore the orbs round the vast circumference in a curvilinear path that oscillated in regular alternations between the exterior and the interior edges. Or, simpler still, it were in consonance with recognised principles that, the equality of mass and of distance being perfectly uniform and balancing at every point, the centre in space should correspond to the centre of force, and the orbs move on with a single and uniform motion in the plane of the ring. No such paths, however, can belong to the stars of the filaments within and without the zone. Locate the centre of force where we may, we distinctly see that their firmamental orbits must be

*We are assuming the plane of vision on which all these systems lie to us to be such that their apparent are actual representations of their true forms. This, however, is of little real consequence; as, in all the cases we have selected, the apparent forms are such that the actual ones cannot be otherwise than complicated and most irregular.

most irregular and undefinable; while their filamental aggregation, their hanging, as they seem to do, loosely together, seems distinctly to intimate that each filament moveth altogether, if it move at all;' that their ratios of activity are far more nearly approximated than, with orbs so differently situated with regard to the common centre of force, we could have anticipated these should be. A similar or analogous difficulty meets us when we examine either the Crab or the Dumb-bell firmament. In the former, indeed, we find that the body or principal part of the system-a not very regular ellipse-exhibits marked crowding together of the orbs toward the centre. This may be supposed to point out either a very great amount of aggregation among the interior orbs, the system being, in this case, a comparatively shallow stratum of stars, with the inner ones closely approximated, and the outer farther removed,―or a mass more nearly globular, the intenser central light being due to the occupation of the field of view there by the entire depth of the cluster, while the edges present the fining and thinning away of the rounded mass. Perhaps the more probable explanation of this peculiarity of appearance--an exceedingly prevalent one-is that which refers it to the conjoint operation of these two causes, the second being, however, by far the more efficient of the two. But in any case, and under any view we may take of the origin of the appearance thus presented, the paths of the stars composing the system are quite conceivable as more or less regular ellipses; and comparatively slight additions to our present knowledge might enable us even to map them definitely out. Not so with the elongated, and either very shallow or sparse filaments of stars, which in this Crab nebula, as in the annular one, present themselves to our observation. Here again, we are baffled in all attempt at definement, or even remote conception of the nature of the orbits described; and the more so, by the manifest hanging together of these filamental appendages to the body of the firmament. Did that central mass exhibit, as in other cases it does, simply a broad environing diffusion of star-dust, somewhat equally distributed, the orbs of this outer region of the system might easily be conceived as each holding on its individual path— a path regulated mainly by the mass of the orb, and its distance from the centre of force. But in the case we are considering, the entire reverse of this equality of distribution presents itself. Distinct strata of stars alternate with corresponding voids; and the maintenance of these coherent filaments, the non-dispersion of the orbs composing them, in ever-varying diffusion over the whole exterior realm,-seems to indicate an equality, or even a conjunction of motion among them, to which known analogies

afford no clue. By the Dumb-bell or Anchor nebula, difficulties of another kind are brought before us. Here, as in many other cases, two central groupings seem to be exhibited; and while, could we isolate these, the firmamental arrangements and motions of each were comparatively simple and easy of definement, the broad and dense belt of stars which unites the two not only is itself a mystery as regards its internal structure and orbitual movements, but it involves in corresponding mystery the more comprehensible portions of the system it unites.

In considering, however, the present incomprehensibility of the motions and arrangements of very many of these firmaments, there is one important fact which should ever be kept in viewthe frequent recurrence, not only of the same general and explicable features, but of essentially the same anomalous and inexplicable ones. Amid all these varieties of irregularity, there is a certain occult likeness which seems to indicate that apparent irregularity is here the fruit of generic principle, and high, farseeing design; to point to some great scheme of evolution in progress, wherein, perhaps, each of these majestic systems may but play the part of an individual mass. This regularity of irregularity; this definedness of the undefinable; this unity of unlikeness to that which our present knowledge deems most simple, most orderly, most harmonious, most perfect, should, we believe, suggest to us the thought that the unrest of these orbs and systems is more than a mere motion in space: is an unrest in time, which is being conducted on, through the instrumentality of principles and laws as yet very imperfectly apprehended by us, through successive phases toward higher and more perfect phase. And yet more decided, though, at the same time, more mysterious, indications of such change are set before us, in the sensible aspects of those systems; indications which appear to point either to disruption or consolidation of them, as the next great stride toward the consummation. Such indications seem, for instance, to be given us, even in those least complex forms where two great nucleated masses of orbs present themselves. It is difficult to look on the Anchor firmament, or the many others generally resembling it, without the impression that these densely massed extremities are destined not always to be bridged together by the intervening zone; that each is gathering in to itself the contiguous orbs, its own clustering and crowding together the while; and that yet these may become two isolated systems, balanced, it may be, and mutually revolving as units in association like that of the binary stars; but each containing within itself the centre of force to its own individual orbs-selfstanding and as a system complete within itself. And when from

this system we turn to Lord Rosse's great conch or spiral one, these indications become at once more decided, and more perplexing and mysterious. Here, also, we find two great and strongly marked nuclei, associated by intervening zones of orbs. But the connecting bond is no longer, as in the former case, a parallel and homogeneous zone; it is made up of an interrupted and complicated succession of deep or crowded, and shallow or thinly peopled patches of orbs. These deeper and more crowded portions seem at first to suggest the idea of minor and independent aggregations in progress there; of a breaking up of the associating bands or convolutions into local systems, which may be destined ultimately to flow in upon and coalesce with the great nuclei, or to subsist as isolated and independent schemes. One very remarkable feature in this singular* firmament appears to corroborate these suggestions. The parts of the connecting zone immediately contiguous to the principal nuclei, present themselves as almost perfectly homogeneous and unbroken ; as if there the great nearness and preponderance of the central force had coerced and restrained the tendency to local aggregation; and the curdling and breaking up of these bands increase as we remove from these mightier centres. We have elsewhere still stronger manifestations of this procession of firmamental disruption and local consolidation. There are systems whose whole surface appears mottled and curdled; a mere congeries of isolated patches, loosely held together by the orbs which at present thinly people the voids between, but which may yet be gathered up to the aggregating masses they adjoin, and leave darkness and silence in the spaces which now they occupy. Nay, in the system which lies most open to our search, and with which are bound up our most immediate present interests-in our own home-firmament these indications are so distinct and decided, that they have been held, from the time of Herschel downward, to show a process of disruption certainly in progress before us. In the remoter portions of the milky way-in the nearer we might more easily confound appearance with reality-and especially on its extreme confines, where the central and aggregating force is weakest to coerce and restrain, these manifestations of disruption and local systematising are abundant and strongly marked. Patches crowded and crowding present themselves, environed by corresponding vacancies; and though in the case of almost all of these there is a connexion with its fellows still by lines of continuous star-dust, and though thus the general aspect is of a glorious net

Not, however, a solitary in its strangeness of wild and glorious majesty. We are informed by Mr. Nichol that Lord Rosse has noted as exact a double of it, as it was so long supposed to be of our own astral system.